The collection of human samples and related data is not a recent practice. However, in the last few decades, such practices have taken much importance mainly due to the creation of population type biobanks. Defined as research infrastructures, they are conceived to last several decades. They invite thousands and, in some cases, hundreds of thousands of participants to contribute their samples, undergo physical and biochemical tests and answer various questions regarding their health and socio-demographic environment. In this context, what are the obligations of these initiatives and the researchers involved therein towards the participants? Considering their duration, what is the legal setting surrounding such biobanks in Québec? These are the two questions addressed by this study. With respect to the legal setting, we propose an analysis based on three axes: i) laws, rules, professional deontology and norms; ii) the legal qualification of the act of banking samples and data; and iii) obligations resulting from the nature of the object of the legal relation. Our analysis reveals that the legal setting surrounding biobanks is a mosaic composed of legislative, contractual, deontological and normative obligations that, despite its complexities and challenges of accessibility for the participant, ensure a certain level of protection for the latter. Regarding the obligations of the biobank and its researchers, they are, for the majority, affected by particularities of population type biobanks. Indeed, specific challenges exist with respect to consent, the obligation to inform, the return of results and the security of samples and data. Given the evolving nature of the theses obligations, we propose to consider an approach based on the best interests of the participants when determining the nature and the intensity of the different obligations applicable to the biobank and its researchers.